"I replace the fat with vegetable oil."
Doesn't really sound like a good idea imho, but who knows?
Otherwise sounds great

True, I was surprised after hearing that. Maybe it was a translation error or something because almost everyone knows milk fat is needed to make good ice-cream.

I don't think it's a translation error. My japanese isn't good so I'm not confident what her exact words are but she's saying shokubutsuyu (vegetable oil).

Edit: Seems like it's pretty common in India to use vegetable oil instead (it's a lot cheaper), you cannot call it ice cream however.